1. Field Of The Invention
This invention relates to thermal transfer recording mediums which are adapted for use in an electro-sensitive thermal transfer recording process and more particularly, to an electro-sensitive thermal transfer recording medium which can be regenerated and is thus be repeatedly usable in the above process.
2. Description Of The Prior Art
A variety of electro-sensitive thermal transfer recording recording systems have been heretofore proposed, in which electric signals corresponding to image signals are transmitted to an ink medium provided with an anisotropic conductive layer and a heating resistor layer, thereby transferring an imagewise ink on a record medium. For instance, in Japanese Laid-open Patent Application Nos. 56-10479, 60-259485 and 1-113276, there are disclosed printing and recording processes wherein a powder ink is deposited on an electro-sensitive thermal transfer recording medium and thermally fused and, thus, an ink medium having the leveled ink layer is provided for use in printing and recording. In Japanese Laid-open Patent Application No. 63-297084, there is described a printing and recording process wherein a powder ink is electrostatically, uniformly deposited on an electro-sensitive thermal transfer recording medium and is transferred to a recording sheet in accordance with image signals.
Japanese laid-open Patent Application No. 62-196187 proposes an electro-sensitive thermal transfer recording medium which comprises a 2 to 30 .mu.m thick metallic foil, a resistor layer composed of a resin matrix and a conductive powder other than metal powders formed on one side thereof, a polyethylene wax ink coated on the other side. The resin matrices include, for example, polyethylene, polystyrene, polyamides and the like. Moreover, Japanese Laid-open Patent Application No. 56-93585 sets forth an electro-sensitive thermal transfer recording medium which has a stainless steel foil substrate and a resistor layer composed of a polyimide and carbon.
However, the conventionally employed electro-sensitive thermal transfer heat recording mediums have the vital problem that they undergoes deformation owing to the application of heat at the time of printing and cannot thus be used repeatedly. For instance, the medium set out in the afore-mentioned Japanese Laid-open Patent Application No. 62-196187 makes use of resins, as the resin matrix, which are relatively low in heat resistance and mechanical strength. During a number of printing and recording cycles, the resistor layer undergoes deformation by application of electrically induced heat and by contact with a head under pressure. This leads to the disadvantage that precisely fine images of uniform quality cannot be repeatedly obtained.
With the case of Japanese Laid-open Patent Application No. 56-93585, the polyimide used cannot ensure good heat resistance and mechanical strength required for the electro-sensitive thermal transfer recording. In a number of printing cycles, the medium will likewise undergo deformation by application of electrically induced heat and by contact of a head under pressure. Thus, the disadvantage is involved in that precisely fine images of uniform quality cannot be obtained.